SMALL INTESTINE Flashcards
Main prognostic factor in small bowel adenocarcinoma
Lymph node invasion
For jejunoileal adenocarcinoma, mortality risk has been linked to …
advanced age, advanced stage, ileal location, recovery of fewer than 10 LN, # of positive nodes
Recurrence of appendicitis in non operative appendicitis mgmt within one year
1/3rd
Overall cost difference between non operative and operative management of appendicitis
Non operative is lower overall
Carcinoid tumor of the appendix 1-2 cm in size. When should you consider R hemi?
- invasion into mesoappendix
- positive margins
- appendiceal base locations
Residual tumor threshold for complete cytoreductive surgery
2.0-2.5 mm
Malignant cells are effectively destroyed by hyperthermia in what temperature range?
41-43 degrees celsius
Location of ampulla of vater on ERCP
12:00-1:00
Location of CBD orifice on ERCP
11:00-1:00
Location of pancreatic duct orifice on ERCP
2:00-4:00
Tx of 1st episode of cdiff, mild to moderate
fidaxomicin 200 mg twice daily for 10 days;
Alternative: Vance 125 mg QID x 10 days
First episode with severe (WBC >15, Cr >1.5) severe c diff tx
Vanco 125 mg PO QID or fidaxomicin 200 mg BID x 10 days
1st episode of cdiff with fulminant (shock, ioleus, toxic megacolon)
Vanco 500 mg QID PO or via NG - if ileus consider adding vanco rectally
Metronidazole 500 mg IV q8h with vanco esp if ileus is present
First relapse of c diff - tx?
If 1st episode was flagyl - give vanco 125 mg PO QID for 10 days
If treated with vanco, do prolonged vanco tx with gradually reduced doses: 125 mg QID for 10-14 days, then 2x daily for a week, then 1x daily for a week, then every 2-3 days for 2-08 weeks OR fidaxomicin 200 mg BID for 10 days
Second or subsequent relapse c diff
VAnco - prolonged tx with gradually reduced doses as described abov e
OR
vanco 125 mg QID for 10 days followed by rifaximin alpha 400 mg TID for 20 days OR fidaxomicin 200 mg BID for 10 days OR fecal microbiota transplant
Screening for CRC in UC
Begin within 8 years of diagnosis, scope every 1-3 years thereafter with >33 random biopsies
Screening for CRC in PSC
Every year
Small bowel mass with calcifications and linear “spoke like” fibrosis of trhe mesentery
Small bowel carcinoid
Increased 5-HIAA excretion in a 24 hour urine collection
Diagnostic but not sensitive for carcinoid unless it is metastatic to liver. Chromograin A is more sensitive. Not highly specific.
How many LN should be removed (ideally) in small bowel carcinoid?
> 7, SEER database showed that this was a/w better outcomes
Where is vitamin B12 complex absorbed?
Ileum. Rsections >60 cm usually result in clinically significant vitamin B12 malabsorption.
Where are bile acids mostly absorbed?
Ileum. Fat malabsorption secondary to bile acid deficiency in those with extensive ileal resection is assoc with increased risk of oxalate kidney stones if colon preserved . Interruption of enterohepatic circulation of bile acids by ileal resection –> decreased hepatic bile acid secretion and altered composition of hepatic bile. Hepatic bile becomes sueprsaturated with cholesterol with subsequent formation of cholesterol crystals and gallstones in gallbladder bile. If >100 cm resected usually there is severe bile acid malabsorption –> steatorrhjea.
Where is the digestion and absorption of protein occurring
80-90% occurs in jejunum.
Where is most of iron absorbed?
Duodenum
Where is most calcium absorbed?
Duodenum
Where are fat soluble vitamins absorbed?
Terminal ileum
MC benign neoplasm of small bowel
Adenomas (or leiomyomas depending on source)
MC location of carcinoid
Rectum > SB
Within small intestine the ILEUM is MC location
Carcinoid tumor of small bowel <1 cm without evidence of nodal mets
Segmental resection
How do you approach SMa
Mobilize 4th portion of duodenum or ligament of Treitz
What to do if unable to cross clamp supraceliac aorta when performing SMA bypass?
Retrograde orientation from right CIA using lazy C configuration
What is the role of secretory IgA in the digestive tract
Blocks absorption of antigens from the gut, protects against the intracellular lysosomes, neutralizes bacterial toxins and viruses
Celiac patients without improvement in symptoms despite dietary modifications - suspicious for?
T cell lymphoma of small intestine (e.g., enteropathy-assoc T cell lymphoma)
Factors that best predict long term outcome and recurrence of GISTs
Tumor size>5 cm, mitotic count >5/50 HPFm, tumor location
Small gastric pouch after roux en y may lead to
pernicious anemia, macrocytic anemia
strongst layer of intestine
submucosa
mc location of small bowel lymphoma
ileum - lymphoid follicules are most prominent here. Usually >5 cm at presentation
Most common location of GI lymphoma
stomach
Which subtype of SI adenoma has the largest potential for malignant degeneration
villous
MCC death among those with FAP who have previously had colectomy
periampullary adenoCA
slow transit constipation who have failed conservative mgmt
total abdominal colectomy with ileorectal anastomosis
Treatment for short gut syndrome
GLP 2 (mucosal growth, prevents gut atrophy, improves absorption), neurotensin and bombesin can also prevent gut atrophy.
Can use H2 blocks or PPIs, abx to prevent bacterial overgrowth, chloleretic agents to improve bilioary flow, bile salt binders to improve diarrhea,anti secretin agents to decrease intestinal secretions and hypomotility agents to increase transit time
As soon as acute phase of short gut syndrome has resolved, enteral nutrition is started. What kind of feeds should they get?
Small amts of iso-osmolar concentration containing high carb, high protein and low fat. Also supplement medium chain triglycerides and fat soluble vitamins as s well as calcium, magnesium and zinc
Mechanism of GLP 1
incretin hormone used in tx of diabetes. Incretins are metabolic hormones that stimulate insulin secretion and suppress glucagon secretion. IT’s released from L cells in the distal ileum and colon after eating.
MC operation for SMA syndrome
duodenojejunostomy
Most common GI lymphoma site (NHL)
stomcach
Stage 1 NHL
single LN region
Stage 1E NHL gi tract
NHL involving single extra lymphatic organ or site
Stage 2 GI NHL
Involves 2_+ ln regions on same side of diaphragm
Stage 2E GI NHL
localized involvement of 2+ extra lymphatic organs or sites
Stage 3 GI NHL
LN on both sides of diaphragm
Stage 4 GI NHL
diffuse or disseminated involvement of 1+ extra lymphatic sites (i.e., liver, bone marrow, lung) with or without LN involvement
MC type of symptomatic intussusception
Ileocolic
Diagnosis of blind loop syndrome
Carbohydrate breath test
Metabolism of carb substrate by bacterial flora leads to production of H+ or methane gas which is excreted in the breath
Highest risk of malignancy in SB
villous adenomas
35-55%
Ileal resection affects absorption of what
Vitamin B12
Vitamin A
Vitamin D
Vitamin K
Bile salts
Oxalate
